diff --git a/utilities/backupable/backupable_db_test.cc b/utilities/backupable/backupable_db_test.cc
index 738e11b914bb007c2f091c7481532cb7c39671b0..69ffa6e562875b3299904af5b31413f84ec19582 100644
--- a/utilities/backupable/backupable_db_test.cc
+++ b/utilities/backupable/backupable_db_test.cc
@@ -614,7 +614,7 @@ TEST(BackupableDBTest, OnlineIntegrationTest) {
 
   std::vector<BackupInfo> backup_info;
   restore_db_->GetBackupInfo(&backup_info);
-  ASSERT_EQ(2, backup_info.size());
+  ASSERT_EQ(2UL, backup_info.size());
 
   // check backup 3
   AssertBackupConsistency(3, 0, 3 * keys_iteration, max_key);